题解 | #有效括号序列#
有效括号序列
https://www.nowcoder.com/practice/37548e94a270412c8b9fb85643c8ccc2
import java.util.*; public class Solution { /** * 代码中的类名、方法名、参数名已经指定,请勿修改,直接返回方法规定的值即可 * * * @param s string字符串 * @return bool布尔型 */ public boolean isValid (String s) { // write code here Stack<Character> stack = new Stack<>(); for(int i = 0; i < s.length(); i++){ char c = s.charAt(i); if(stack.isEmpty()){ stack.push(c); }else if(stack.peek()=='('&&c==')'){ stack.pop(); }else if(stack.peek()=='['&&c==']'){ stack.pop(); }else if(stack.peek()=='{'&&c=='}'){ stack.pop(); }else{ stack.push(c); } } return stack.isEmpty(); } }